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Setting Limits on Supersymmetry Using Simplified Models

Setting Limits on Supersymmetry Using Simplified Models

Published on: November 15, 2013

Breakdown of the narrow width approximation for new physics.

D Berdine¹, N Kauer, D Rainwater

¹Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA. berdine@pas.rochester.edu

Physical Review Letters

|October 13, 2007

Summary

This summary is machine-generated.

The narrow-width approximation simplifies high-energy physics calculations but fails for new physics. Ignoring finite width effects leads to significant inaccuracies when reconstructing new physics models from data.

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Area of Science:

High-energy physics
Theoretical physics
Particle physics

Background:

The narrow-width approximation is a common technique to simplify scattering calculations in high-energy physics.
This approximation works well for the Standard Model but is not generally applicable to new physics scenarios.

Purpose of the Study:

To investigate the validity of the narrow-width approximation in the context of new physics.
To quantify the corrections introduced by considering finite width effects in scattering calculations.

Main Methods:

Performed fully off-shell calculations for scattering processes.
Included finite width effects, considering decay matrix elements and phase space.

Main Results:

Identified numerous instances of significant corrections when finite width effects are included.
Demonstrated that decay matrix elements contribute substantially to these corrections, beyond phase space effects.

Conclusions:

The narrow-width approximation is unreliable for new physics beyond the Standard Model.
Failure to account for finite width effects, particularly decay matrix elements, leads to substantial inaccuracies in reconstructing new physics Lagrangians from experimental data.